I was curious how Imgur was rendering their upvote/downvote arrows:
I assumed they were images, but I found something that I did not expect:
A custom font that contains glyphs for up and down arrows, mapped to the 'o' and 'x' characters, respectively:
Is this method considered acceptable these days? I have never considered using a custom font for something that doesn't semantically map into an alphabet. This approach is not even on my radar of best practices for web design.
I can imagine the reasons for:
Your site uses a standard icon set that can be mapped to single-character codes.
You only need control over foreground/background color for the icons.
You want icons that scale the same as text.
I want to know any specific reasons against using this method.
In particular, I'm looking for answers that address any of the following:
browser/platform compatibility
future maintenance implications
semantics
performance
standards compliance
The only thing I have come up with so far, is that, semantically, it does not make sense to map an upvote icon to the character 'o' and a downvote icon to the character 'x'. And, just to be specific, I'm not talking about keyboard mappings, but rather language mappings, character codes. It seems to me that raster images or SVG are much more preferable alternatives in this case.
I thought of one other possibility: language and encoding compatibility. Would the html lang attribute or character encoding of the page have any effect on the character mappings into the font in the CSS stylesheet (the stylesheet uses 'x' to represent a downvote icon)?
However, I'm certain Imgur has thought all of this through already. So, why am I wrong?
Modern browsers (e.g. IE9 above) support custom fonts.
Even Bootstrap also uses custom fonts for icons, known as Glyphicons! It is a nice way to beautify the websites icons without having to do it from Photoshop as an image which may cause responsive issues.
They are usually used by calling the class name which links to the CSS that call the icons from the font family. Html lang would not have any issues with it.
Many websites use "icon fonts". But yes, assigning language letters to them would be wrong. It would be best to assign an arrow icon to the Unicode character code for a similar arrow. Another option would be to use the Private Use Area of Unicode. In this case, if your font fails to load for any reason, you won't have a good fallback strategy. But if you choose meaningful char codes for your icons, you would.
Many people are in favor of using SVGs over icon fonts. But there are pros and cons to both icon fonts and SVGs. I think that it's great that as web developers, we get to choose among different implementations or solutions to the same problem.
To answer your question, I would say that if done right, there is nothing wrong with using fonts for implementing icons.
As Mike 'Pomax' Kamermans put it:
"Fonts are for encoding vector graphics that are to be used in
typesetting context. That can mean letters, or icons, or emoji"
One big reason is accessibility. There are many browser extensions which swap out a website's font for one that's more legible for people with different visual impairments. If you use fonts for your icons, these will be swapped out too, leaving your user looking at whatever string you placed in for your icons.
Related
I am making an application, and I want to add a "HOME" button.
After much struggling with various icon libraries, I stumbled upon this site,
http://graphemica.com/%F0%9F%8F%A0, with this
🏠
A unicode symbol, which is more akin to a letter than an image.
I pasted it into my HTML, and it just workedTM.
All this seems a little too easy, though. Are unicode symbols widely supported? Is there some kind of problem with them that leads people to use icon libraries instead?
It depends on what do you mean for "safe".
User should have the fonts, so you must include the relative font, and in various formats: there is not yet a format recognized by most used web-browsers.
Additionally, font with multiple colours are not fully understood by various systems, so you should care about what do you expect from users (click, select, copy, etc.).
Additionally, every fonts has own design, so between different fonts (so browsers and operating system) things can look differently. We do not have yet a "Helvetica 'Home'", a "Times New Roman 'Home'".
All this points, could be solved by using a web font, with monochrome glyphs (but it could be huge, if it includes all Unicode code points (+ usual combinations).
It seems that various recent browser crashes if there are many different glyphs, but usually it should not be a problem.
I also recommend aria stuffs so that you page could be used also by e.g. readers (and braille screen).
Note: on the plus side, the few people that use text browser can better see the HOME (not the case in case of an image), if somebody still care about this use case.
Some things you want to make sure you’re doing:
Save your HTML file as UTF-8. In fact, save all text files as UTF-8 unless there’s some reason you can’t.
Put the line <meta charset="utf-8" /> near the top of your HTML file.
Make sure your server isn’t misconfigured to tell all browsers that webpages are in the wrong encoding.
If, somehow, it is and you can’t fix it, fall back on &entities;.
Specify a font stack for your emoji in CSS with a set of fonts that cover nearly every system, perhaps including Apple Color Emoji, Noto Color Emoji, Segoe UI Emoji and Twemoji.
If a free font such as Noto or Symbola contains the emoji you use, you can package it as a WOFF to be sure it will always display the way you want. (As of 2018, Tor browser does not show most emoji correctly by default, but mainstream browsers do.)
I think using unicode is a good practice for development. Beacause The unicodes are essentially part of your operating system so you don’t need any special library or plugin and you treat them like regular text.
The only problem is - code can be defficult to read or understand. I think it is not easy to understand that (ㇼ 8;🏠) printing home icon.
Even the 8 bit PNGs are faster then the font icons.
Image icons can be lightweight but still slow down your site with another HTTP request and time for the image to load. With images you don’t have flexibility over the color and scaling. SVG vector image alternatives are still not faster than plain-text (Unicode characters). Unicode doesn’t require additional HTTP requests and can be made to scale nicely.
If you are developing a website using only simple shapes, you can use unicode UTF-8 symbols as replacement for font icons.
I think :
Almost every developer use libraries for icons because of readablility of code, Easy to use and get more options.
Safe or Not
I can not say whether it is safe or not.
Because Unicode contains such a large number of characters and incorporates the varied writing systems of the world, incorrect usage can expose programs or systems to possible security attacks. This is especially important as more and more products are internationalized. This document describes some of the security considerations that programmers, system analysts, standards developers, and users should take into account, and provides specific recommendations to reduce the risk of problems.
Read about UNICODE SECURITY CONSIDERATIONS
Here are few precautions to be taken while doing that, I did some research and found this to be more helpful for your question. Also I dont know how you can do but credits go to Mr.GOY
Displaying unicode symbols in HTML
I am editing a pre-existing site that makes use of icons/glyphs in a multitude of files like eot, svg, w0ff, ttf (I guess for various compatibility). It calls these with the use of the font and a CSS value like this:
font-family: icons_filename;
content: "\e601";
So how would I find a list of the different values of the icons called with "content"?
In other words, I am trying to see what is possible in an undocumented library of icons that don't necessarily have a good list of names.
I also don't understand how the value "\e601" is used or how to look that up in a file. This part of CSS is unfamiliar to me and I cannot find a good explanation for this as most icon tutorials only show how to use a documented library.
Thanks
I believe you're looking for UTF-8 characters. Icon fonts generally override the default font on this universal icon font if they exist. Here's a link to where you can view them.
Adding onto what Chris already said, you should be able to track down which font icon library your template/theme is utilizing. One of the most common examples of these would be Font Awesome.
From the link above, you'll have the ability to go through each icon and figure out which "unicode" to select. For example, "fa-blind" (blind man walking icon) has a unicode of "f29d", which translates to "\f29d" when using it for the CSS property "content"
If your stylesheet is served in UTF-8, you can avoid the need for unicodes (f29d in our example), and directly copy/paste the icon should it be listed on a site for you (i.e, instead of "\f29d" in the content, it'll be the actual fa-blind icon glyph. It'll show up as a blank square in your CSS document, but will render properly when you're on the webpage.)
I might've gone on too long here, but ultimately what you need to do is figure out which library of icons the site is utilizing. We could easily figure it out for you if a link is provided.
I would like to use the UTF-8 character ✖ on my site but I am not sure if this will be supported cross browser.
I am worried that:
a) Users will not have access to a font containing that character
b) IE will not find the character even if the user has a font that could display it. I am worried about this because of this info:
By the specifications, browsers should display a character if there is any font in the system that contains it. If the fonts specified by the author (in CSS font-family settings or, rarely these days, using font markup in HTML) do not contain the character, browsers are supposed to use fallback fonts. The same applies if no fonts are specified by the author; browsers should use primarily their default fonts, using alternate fonts for any character not covered by the primary font.
In practice, things don’t always work that way. Especially IE is notorious for its failures in this respect. It often fails to display a character, even though it could do that if it used all the fonts in the system. If a browser cannot render a character, it may show a small rectangle, possibly containing a question mark, ?, or some similar indicator. Here’s a quick test (character U+0840, which is probably not supported by any font on your computer): ࡀ.
Source.
c) Other issues that I have though of.
There is a resource called Unify, that will show what devices the character is supported on but it currently (Sept 14, 2015) only suport 107 characters.
So to summarize, the question is: How can I determine if it is safe to use a utf-8 special character on my site? Is it safe to use ✖ specifically on my site?
It's always safe - your user's computers won't suddenly burst into flame.
From a technical perspective, your best bet is to use a web font that has support for every Unicode character you want to use. That is not a catch-all (the user might have web fonts disabled or is using a command line browser, etc...), but it should support the vast majority of computers.
From there I would apply common sense. If the displaying of a character is absolutely crucial and lives depend on it, try to not use Unicode. Otherwise I'd say 'go ahead'.
This is as much a UX question as it is a technical one, so I will mention both.
As a comparison, on my IE11 browser, it looks like this: , but on my Firefox 31.8, it looks like this: . A good user experience is generally associated with consistency, and this approach is not very portable. So from a UX perspective, this is not a great solution.
I would say using a tiny *.gif or *.bmp, or even *.png if you need transparency, is a better solution. Even better yet, go with *.svg so scaling will not be an issue. From a technical aspect, the overhead of something that small is generally insignificant.
The only problem you can face is that exotic symbols are not implemented in many fonts, so the user can see a dummy character (e.g. square) instead of this. I personally like to use svg symbols for this purpose.
An alternative solution would be to use a web font with those icons in it (although probably a subset version of, so that it's less and 1 kb and doesn't weight down your pages).
I am currently using the utf code "\293B" for an arrow to put before the reply link in posts. the html is declared utf 8. The arrow works in firefox and explorer but not chrome. i saw that wordpress uses content: "" ("\f412";) (for example here:http://cinematicamsterdam.wordpress.com/2014/05/26/cinematic-city-a-retrospect/) that works accross all browsers but I can't paste it in my document. How can I do it?
i'm a newbie here, sorry if the question is simple..
This does not primarily depend on browsers but on fonts installed in the system; secondarily it depends on your CSS settings and on some shortcomings in browsers. For a general description of such issues, see my Guide to using special characters in HTML.
In particular, U+293B BOTTOM ARC ANTICLOCKWISE ARROW “⤻” has rather limited font support. A large number of systems have no font containing it. It could be used rather (though not 100%) reliably using a downloadable font, but it sounds like you are generating HTML-format e-mail messages, so downloadable fonts are hardly a feasible option.
The best short appears to be to an image instead.
What your describe as WordPress usage is a Private Use codepoint. In practice it works only with a particular special font. You can copy and paste it, but outside the private use context such as use on a web page with a specific font, it has absolutely no meaning and should not be expected to have any particular rendering, or any rendering at all.
In our web app, we're using colored stars (★ aka ★) to represent a rating. So the first four stars would be a solid color while the last star would be white to represent a rating of 4 out of 5. Like so:
What concerns does this raise in terms of accessibility and support?
I can't be certain that the version of the font in the user's browser supports this character, what are some methods to provide "graceful degradation" to this? Or is the coverage good enough that this is not an issue?
How is this "rendered" by a screenreader? Would wrapping the rating with a <span title="4 out of 5"> provide more accessibility?
The general question in the heading is very broad. To address it briefly, the main concern is font problems, which can be rather serious, and there is really no graceful degradation; for a longer answer, see my Guide to using special characters in HTML.
The specific question about colored stars is much simpler, and the short answer is that there are strong reasons for using five images, each with a different number of colored stars. Then you can use meaningful alt attributes, like alt="four stars", and things work rather reliably. They should be content images (via img), as there is no way to specify textual alternative to a background image.
Considering the possibility of using the BLACK STAR “★” character, its font support is not particularly bad but not very widespread either. There is no simple way to find out the percentage of computers that have some font containing it. Moreover, if the character exists in some font(s) in the system, its appearance may vary a lot. For this specific character, glyphs can be expected to look rather similar – but in different sizes.
If your context really required the use of a symbol as a text character, then you may need to take risks, but here the symbols accompany text instead of really being contained in text, so it’s OK to use images.
Using an embedded font via #font-face is possible but sounds overkill here.
Screen readers vary a lot in their treatment of special characters. In general, they have been designed to read normal text in some human language(s), and they often fail to speak special characters meaningfully – or at all, even by simply saying the name of the character. The title attribute may be spoken, but usually as an option only, and the user may be unaware of the existence of such options.
Images cause some HTTP requests, but this is of marginal or ignorable impact. (You could use CSS sprites, though that’s hardly useful in a simple case like this.) The images typically get cached well. They can be scaled to match text size if desired, e.g. by setting the height of img elements in em units (and not setting width, so that they get scaled so that width:height ratio is preserved).
For best overall compatibility use an image. You know what it will look like, the accessibility concerns are straightforward, and you don't need to worry about browser support for various features.
I think if you don't want to experiment, you should follow Jukkas advice and use an img element.
If, for whatever reason, you want to use the Unicode star symbols, you'd have to try to make it accessible. According to your description, I guess you currently do something like this:
<div class="rating">
<span>★★★★</span>★
</div>
<!-- CSS: .rating span {color:yellow;} -->
This example doesn't mark-up the semantics of the rating, and therefor screenreaders and other user-agents can't "understand" (announce) the meaning of it. The rating score is only described by color → this is not accessible.
A possible way might be the use of the abbr element, however, this use case could stretch the definition too far ("Are the five stars really an abbreviation of a rating score?"):
<div class="rating">
<abbr title="rating of 4 out of 5"><span>★★★★</span>★</abbr>
</div>
<!-- CSS: .rating span {color:yellow;} -->
You could use a #font-face from font squirrel. If the rating will never change, then how about creating an image using Photoshop or similar program to use as a background image? The title for the span is not a good one. What happens if you later change the rating, then you have to go change all the title attributes. I would make a more general title like "Rating". If the rating isn't absolutely necessary for your content on the page, consider using JavaScript to display the rating. That way, you don't actually change the HTML, therefore your security concerns should be handled.